Introduction

I've been tracking the discussions over at the evolution and creationism pages for some time now. As someone with a healthy science background, I find the debate between evolutionists and creationists very interesting, as many common misconceptions about science typically come out of this discussion, and often from those representing both sides of the issue.

A Scientific Approach to the Debate

First, it's necessary to understand the position of each side in the evolution/creationism debate: what does each side want?

In this case, the controversy is usually over whether creationism should be taught, or even mentioned, alongside evolution in public school science classrooms. The evolutionists say no, the creationists say yes. How can we apply the understanding of science, scientific fact, and scientific theory to this debate in order to answer such a question?

What Is Science?

What is science? This might seem like a fairly silly question...everyone knows what science is, right? I find that there are a few subtleties that can trip people up, especially in a discussion which has such deep-rooted meaning for both sides as the evolution vs. creationism debate. Now, as I said above, I'm a science guy, so it shouldn't surprise you that I don't recognize creationism as "science" any more than I recognize astrology or numerology as sciences. Unlike many laypeople on the evolution side of this debate, though, my background allows me to explain concisely what science is in a general sense with respect to this debate, and then you can decide for yourself whether creationism is science.

Is Creationism Science?

If one side in this debate wishes to teach creationism in science classes, it makes sense to determine whether creationism is science or not. Creationists claim that creationism is as much a scientific theory as the theory of evolution. Determining whether this is so turns out to be fairly straightforward. Is creationism a predictive model, based on scientific facts, that is restricted to a well-defined problem domain?

Using this definition, creationism is clearly not a scientific theory. I feel I could attack this question on many fronts, but remember that creationism must only fail one of the characteristics of theory-hood in order to be judged unworthy of being taught in science classes. So, I will choose the easiest position to defend as my primary argument: creationism is not predictive in any way. Creationism is indeed a complete explanation of how life came to be as it currently is, and one may argue about the validity of this explanation, whether it is fact-based, works within a well-defined problem domain, etc. Regardless of how those arguments come out, at most creationism still only provides an explanation of the past and how humankind came to be, but no testable predictions at all. In this respect, astrology is closer to being a scientific theory than creationism; at least horoscopes attempt to make predictions.

Is Evolution Science?

One of the most commonly mounted arguments by creationists is that creationism is as scientific as evolution, and since evolution is taught in science classes, then creationism ought to be taught there as well. Conversely, any reason that would exclude creationism from being taught in science classes could also just as easily be applied to evolution. In other words, it's not enough to merely show that creationism isn't science, we must also show that evolution is.

To answer this question, it is first necessary to differentiate between the fact of evolution and the theory. So, I will refer to the fact of evolution simply as evolution from here on out, and I will refer to the theory of evolution as either the theory of evolution, or Darwinism.

(For those who care about pedantics, I am aware that Darwinism specifically describes Charles Darwin's theory of evolution proposed in The Origin of Species, whereas the phrase theory of evolution refers to a current theoretical model that encompasses ideas after Darwin's time, such as punctuated equilibrium. For the purposes of this essay, such distinctions are unnecessary.)

The Fact of Evolution

Is evolution a scientific fact? Do organisms evolve? A definition is in order: when discussing organisms, evolution is phenotypical changes based upon genotypical changes in a population over generations in response to environmental stress.

Sometimes, the genetic variety present in a given population does not allow for the survival of even a single member in the presence of a particular environmental stress factor. In this case, the entire pool of organisms die out. In other cases, most all of the organisms already happen to share a characteristic that is well-suited to deal with the new stress, in which case the population as a whole may barely notice it. In either case, any evolution that occurs due to the stress factor does not differentiate between individuals based on their characteristics; either all of the organisms live or all of the organisms die with respect to the stress factor.

There are situations, however, in which a stress factor affects some members of the population differently than others. In this case, if some of the organisms enjoy characteristics that allow them to reproduce while others do not, and if those differentiating characteristics can be passed to offspring (i.e., they're determined by the genetics of the organism), then evolution has been observed to occur. Note that I do not say that evolution does, in a general sense, occur, or that it will occur, but rather that a specific instance has been observed to occur. With a bacterial culture, a few drops of the right toxin, and a Petri dish, anyone may observe the scientific fact that evolution occurs. Anyone familiar with the increasing potency of antibiotics over the last several decades understands that the drugs of yesterday are no longer effective because the targeted microbes have evolved.

The Theory of Evolution

What about the theory of evolution? Is this a veritable scientific theory? Has it allowed us to make testable, accurate predictions within a specific, well-defined problem domain? Indeed it does. To see that this is true, one may perform an experiment using the aforementioned bacterial culture, toxin, and Petri dish. With an understanding of the theory of evolution, you could predict that descendants of the initial culture will become progressively more resistant to a particular toxin or antibiotic. Predictions that follow from the theory of evolution such as this have been tested and have been shown to be accurate time and time again.

It is important to note that the above example is insignificant compared to many others that have been shown. Many past predictions based on Darwinism are now recognized as scientific fact, while others have allowed us to expand the problem domain. Of course, there are still areas of the problem domain under test that have not been definitively included. It is important to recognize these areas for what they are, opportunities to expand the utility of the theory. If the theory is found not conclusively applicable in a given area of test, it would be incorrect to conflate this finding with the notion that the theory is not conclusively applicable anywhere.

Conclusion

Based on a simple understanding of science and the careful definition of terms, it is clear that creationism is not a scientific theory and evolution theory is. At this point in the discussion, nothing more is needed to determine what type of public school classroom ought to address each; creationism should be presented in religion or cultural mythology classes and evolution should be taught in science classes. Teaching creationism in a science class makes as little sense as teaching evolution in a religion class (so it is with some irony that many creationists argue that evolution is as faith-based as creationism—I hardly think most of them would allow the teaching of evolution in religion classrooms).

Addendum

My framing of this debate has been challenged several times now. I have been told that the "real" debate is not whether it is ok to teach creationism in science classes, but instead whether it should be taught in public schools at all.

I have no problem with teaching about religion of any kind in public school as long as the following rules are observed:

Religion must only be taught in public school on an elective basis. No public school student should be required to take a course about a particular religion. (Requiring public school students to be knowledgable about religion in general on a non-elective basis, on the other hand, is perfectly legitimate and ought to be left up to the school and the community.)
Religion must not be taught in public school from a position of advocacy (either for or against).
Religion should be taught in the contexts in which it makes sense. For instance, all of the following are examples in which religion had an impact on historical events: (a) the Crusades, (b) the Spanish Inquisition, (c) the Salem Witch Trials. Similarly, in a debate, philosophy, religion, or mythology classroom, it could be legitimate to discuss specific religions as long as the above rules are followed. To completely forbid mention of religion in public school classrooms in these contexts would do a disservice to our students—religion is a part of the world; why should students be disallowed from studying a significant aspect of humanity?

I feel that both sides in this debate often attempt to change the position of the other side to make it more extreme and therefore more easily disputed (known as the fallacy of making a straw man argument). So, it is very important to understand the debate; creationists (the creationists to which I'm referring, anyway—I understand there are a great number of people that fall under this heading and not all of them share the same position in this controversy) advocate the teaching of creationism in public school science classrooms as a legitimate scientific theory, to be given equal time with evolution. Evolutionists (again, the ones to which I'm referring) do not want creationism to be taught as a scientific theory and instead want it to remain outside the public school science classroom.

Most evolutionists are also people that want to maintain a separation of church and state. How church and state should remain separate is not unanimously agreed upon; some believe, as I do, that as long as religion is not taught in public schools from a position of advocacy and it is only taught in context to the subject under study (which could even be the subject of religion itself), it is a beneficial component of a public education. There is a minority of those that advocate an extreme position that, under the separation of church and state, the topic of religion should not be broached at all under any circumstances in a public school environment. Creationists often conflate this extreme viewpoint with the more moderate evolutionist stance akin to my own. This is intellectually dishonest because it refutes a weaker argument than is being presented—the classic straw man (and it's not very Christian, if you ask me).